Steam generator



June 3, 1952 R. J. BOYER 2,599,316

' STEAM GENERATOR Filed Aug. 8, 1947 3 Sheets-Sheet l INVENTOR Fig 1 Ifiaymond Jfioyer ATTORNEY June 3, 1952 BOYER 2,599,316

STEAM GENERATOR Filed Aug. 8, 1947 5 Sheets-Sheet 2 0000000000 0000ooocoocooononoo INVENTOR fia'g zona J Boyer i ATTORNEY R. J. BOYER STEAMGENERATOR June 3; 1952 5 Sheets-Sheet 3 7 Filed Aug. 8, 1947 INVENTORayzzzond TTORNE the :inlet of the gas pass. heater tubes form extensionsof the tubular-parts Patented June 3, 1952 STEAM GENERATOR estfield, .N.J., assignor to :Raymond J. .Boyer, M7

The Babcock -& 'Wilcox Company,

New .York,

.N. Y., acorporation of NewJersey 'ApplicationiAugust 8,1947,.Serialflo."7.6!1;581

' :8 Claims. (01. 122-478) .1 This invention :relates ":to .:steam.generators. The invention isa water tube. steamgenerator including avertically elongated :furnace, :the walls of which are definedby steamgenerating tubeswhich provide :the major part of the steam generated bythe installation. The :furnace gases :flow laterally "from the furnaceacross horizontally spaced upright steam generating tubes and then .toan "upright'gasgpass in which part of .a high temperature :superheateris .dis- :posed. The :remainder -.of thesuperheater consists of uprighttubular sections constituting a bank of tubes disposed between thefurnace and The upright-superof .the superheaterin the :gas- .pass: so.that :steam flows transversely ofzthe :flow :o'figases in thegas pass,then through therupright :tubular sections between the gas 'pass and thef urnace,- -and then through other parts .of the superheater tubes to asup'erheater outlet "on the opposite :side ofthe gas .pass from theiurnace.

The invention provides :steam .at a;high;superheat with minimumrequirements :for high :cost alloys for parts of :a .isuperheaterdisposed in a high temperature 'gas zone. It also provides .a

steam 'generating installationin which the superheater tubes areaccessible through an external outlet header which, by :reason .of thetype of superheater construction can be 1 disposed :at :such a positionthat troublesome .and :complicated provisions for gas .sealing the :wallconstruction 'around the superheater :tubes :adjacent the header areunnecessary. i-Byi-virtue :of the particular construction of thesuperheater utilizing continuous tubes which provide a horizontal "bankof tubes inan upright gas passgand 'a-sub- 'stan'tially: spaced upright.bank oftubesrat al'high temperature gas zone, the superheater outletheader is also so 'disposedthatithe tubular steam conducting elementsextending therefrom can be constructed and arranged atiminimumncost andwith a minimum interference with the associated .rparts of theinstallation.

The: invention as specified-.aboveis particularly advantageous when thesuper-heater is divided into high temperature and low a'temperaturesecti'ons having tubes constructed in the manner tween -the twosuperheater sections. :In this event, a plurality of superheater headersare needed, together with a number of high pressure ,Jsteam con'duitsfor conducting "steam from one section' to-the *attemperator, back fromthe attemperator 1 to the other. superheater .section, and then .iromthe other superheatersection to a point-0f use.

The super-heater of the invention .is .of such construction that water,:used .to protect the superheater tubes in starting up,-can .be-readilydischarged from the tubes when-steamis about to pass through the tubesunder :operativeconditions. Under .-a banked :condition,.the.-superheater tubes can be maintained undenegualized temperature{conditions inasmuch .as the construction inherently tends "to :avoid acondition wherein one part of the .superheater contains Water andanother part vcontainssteam or water vapor. The superheater alsofacilitates the .removal of scale accumulations in the superheater tubesby washing or chemical cleaning.

The invention "will be-zdescribed :withwreterence to the accompanying"drawings :which show a preferred embodiment .-of the invention, and

other objects of the invention-will appeamasrthe accompanyingdescription proceeds.

In :the drawings:

Fig. 1 :is "a vertical ,section through the aillustrative steamgenerator;

Fig/f2 'isia partial vertical section .on the :line 2-2 of Fig. :1,illustrating the arrangement-10f superheater and economizer :tubes;

Fig. .3 is a horizontal section-on the qline 3- 3 of Fig. 1.; and

Fig. 4; is. a partial horizontal :section on the :line 4- 4 ofFig- 1.

The steam generator shown in the drawings includes a primarycycloneiurnace lfliromwhich burning fuel and combustion :products rpassthrough the intermediate furnace =:chamb:er .12 to the-secondarycombustion chamber 14. This furnace construction and arrangement is:particularly adapted for burning crushed coal under high temperature 7conditions, the slag being idischarged from the "hearth 15 through theslag tap opening ll.

The 'furnace and combustion chamber walls are defined by rows of steamgenerating tubes connected to discharge steam and waterinto the steamand water drum 22, some of the tubes being connected into the boilercirculation system by appropriate conduits between lower headers such as28-29, and'the large diameter upright downcomer 3| disposed at the sideof the installation and'connected't'o the water'space of the drum 22.

The high temperature section of the furnace, including the oycl'onefurnace ;l 0 and *the intermediate '"furnace chamber I 2, has theiurnaoe At the upper part of the secondary combustion chamber l4, asillustrated in Fig. 1, the, gases turn to the right and pass across abank of upright steam generating tubes 38. As shown, these tubesdirectly connect the drums 20 and 22.

Beyond the bank of steam generating tubes 38, the gases flow over thesuperheater sections and then downwardly through the gas pass 32 overthe tubes of the economizer 34. Beyond the economizer, the gases passthrough the tubes of the primary air heater section 34 and then continueover the tubes of the low temperature economizer section 35. Whilepassing over this economizer section, the gases turn and then passupwardly through the tubes of the secondary air heater section 38,andthen through the duct 48 which leads to the tubes of a third airheater section 42. From the gas exit side of this air heater section,the gases pass to the flue 44. Ap-

propriate gas pass walls combine with the furnace and the combustionchamber walls to provide for such movement of the gases.

From the steam and water drum 22 tubes 58 lead to a primary inlet header52 of the superheater.

tubes are aligned to define the roof 54 over the Intermediate sectionsof some of these gas pass '32 and beyond this roof, upright sections ofthe tubes 50 define the wall 56.

From the super heater inlet header 52 the steam passes through rows ofmultiple-loop superheater tubes forming the bank of tubes 58. From thisbank, the tubes continue through the vertical tube bafiie B8 and thenhave looped sections 62 and 64 extending'upwardly at a positionrearwardly of the bank of the. tubes 38, rela- 'tive to gas flow. Steamflows upwardly through the sections 62 and 64, then downwardly throughthe connected loop sections 66 and 88, and then horizontally through theupper tubes 89 of the bank of tubes 58 to an intermediate superheater,

header 10, the sections 62, 64, 66, and 68 constituting an upright bankof superheater tubes.

From the header 18 the superheated steam passes through an externalconduit 12 to'an attemperator 14 within the drum 2B.

16 to the inlet header [8 for the second superheater section 80. Thissection, as shown in the drawings includes a bank of multiple loop tubes-with their successive tubular elements extending horizontally back andforth across the downward gas flow within the gas pass 32;

, I The tubular elements of the superheater section 88 'are extendedbetween the tubes of the bafiie 69 so that the steam then flows throughthe upwardly extending loop sections -82 and 84, then through theconnected downwardly extended loop sections 86 and 88, and then throughthe top I tubes of the horizontal bank of superheater tubes 80. to theoutlet header 90 of the superheater. From this header the steam flowstoa point of use.

-.O.the total surface of the primary superheater section less than halfis formed by the tube .-sections, 62, 64, 86,-and 68 which extendvertically From this T attemperator the steam flows through a conduitacross the horizontal flow of furnace gases. These vertically extendingtube sections are more widely spaced and are made of a steel of higherheat resistance than the steel involved in the horizontally disposedtubes of section 58. Similar arrangements and considerations apply tothe bank of tubes 80 and the comparison of their surface to that of thetube sections 82, 84, 86 and 88.

Because of the fact that only a smaller proportion of the totalsuperheater surface (the upright superheater tubes) is exposed to highertemperature gases, the additional expense involved for the more costlymetal of these tube sections is minimized.

The illustrative steam generating installation also includes aneconomizer having upright wall cooling tubes 92 and 93 at the oppositesides of an upward extension of the gas pass 32 two of such extensionsbeing separated by the rows of upright tubes 92 and 93 (see Fig. 2)which may be utilized to support the horizontally extending coils of themain economizer section 34 immediately below the superheater tubes ofsection 58. As illustrated in the drawings (Fig. 2), the tubes 92 havetheir upper ends connected to a horizontal header I00 and the tubes 93and 94 are similarly connected to a similarly and intermediatelydisposed header I82. These headers and a header similar to header I89 atthe opposite side of the gas pass are directly connected to the steamand water drum 22 by circulators such as I 84 and I 06.

The feed water enters th horizontal return bend tubes of the secondeconomizer section 38 through an inlet conduit H8 and, after passingthrough these tubes, flows through the connecting tubes H2 to inletheaders such as the header H4, of the economizer section 34 (Fig. 1).The Water flows back and forth through the return bend tubes of thesection 34, through the upright wall cooling tubes such as 92-94 (Fig.2) to the outlet headers such as I88 and H32, and then throughcirculators such as I84 and I88 to the water space of the drum 22.

As illustrated, the economizer section 35 is functionally disposedbetween the air heater sections 34 and 38 (relative to gas flow) withthe air inlet at the top of the installation as indicated at H6 inFig. 1. From this inlet the air flows horizontally as indicated by thearrow I I8 across the upright tubes of the first air heater section 42and then downwardly through the upright duct I28 to the spaced uprighttubes of the intermediate air heater section 38. The air flowsdownwardly around and between these tubes and is then guided in turningto the left (Fig. 1) by the angular baffles I2 l|23. The air then turnsagain and flows upwardly over and between and around the spaced uprighttubes of the air heater section 31 to an outlet I26 which is connectedto an appropriate chamber from which the heated air is supplied to theburner of th primary furnace Ill.

The wall 69, between the bank of steam generating tubes 30 and theupright parts of the superheater, i defined by tubes I48 and I42 whichdirectly connect the upper and lower drums, 22 and 29, respectively. Thelower parts of these tubes are in single row formation along the wall orbafli I44 which extends obliquely upwardly, and past the superheatersection 58. Alternate tubes, I42, are bent out of this single rowarrangement above level of the horizontal superheater sections 58 and 88toprovide for gas flow to the gaspass 32. Beyond this position the tubesI48 and-.142 sex-tend throuehethesrpef dl to;-the 22. .iQtherstuhllarstensions of tim ofstheitubesof rthegwall fifile. tenderer he superheatersection 150'. and ;;then term a partof th tarchiorlroof theton-ofcaspass3.; :t. tensions-take: the place, ofsome th tub c. ,whichact asdirectiverticalhan ersi r ,th aheade -52.

,nmtheupn r portion of theses pas t athe ,saturatedssteam asnpply-e ubid 3 1 13338 econoimizerioutletewalll;:tubesasucnas fizefiizan effectiveto absorb heat from a W. gthese stubes .-:act;-as-;;Wa11, idefinn 1 411tubes:for.-;the;g as pasststructune.

sWhatfismlai-med is:

azatertub ,steameenera ne n l ti o. unnac suprieh st amisen ta 'ns he:some ef tvhic-hyin .vt l tube f 1 1 -meansefbr connectingsaid:steamgenerati-n tubes to the ,,-circulation systempf the ;-installation, J ans mltoviding for EhBjIatBIQJJHOW Of gaSQ -tfijQm thefurnace acrossisomeof the csteamsgeneratine gtubesand then to anuprightjga-s passrbeyondzath isteam generating ,tubes, ,a superheateraincluding as headerattheside ofisaidigas spass opposite the=.fnrnace,--the superheater including tubes having :series connectedparts donning :,a bank .of verti- ,eally paced itubes extending.agenerally hOIiZDnltally acrossthe flow ofgases inisaid gas pass andupright parts ;forming a vbankpf horizontally gspaced-gtubesdisposedbetween the gas pass and .;sa id;-furnace ;.and series connected..with the :first parts, and means connecting tnersuperheater 5 thefluidsystemto provide for the fiow of steam to the superheater, saidupright parts being directly connected only at their 'upper ends andconnected for series flow to th e horizontally.. extending superheatertube parts atthe lower ends of the upright parts to render thesuperheater drainable by gravity.

2. In a steam generator, upright steam generating-tubes some of whichdefine the walls of a {furnace meansfor-firing-thefurnace, asteamgand-vv{ater drumito which the tops of the steam generatingtubesareconnected, a first superheatensec- --tion includi-ng verticallyextending tubesgdisppsed a high temperature gas zone, second superheatersection including spacedhorizontally extending tubes extending ac'ross'the downward flow of gases in a gas pass-beyond the furnace wall Eitubesexposed A to the heat. of .the furnace gases in the gas turning space atthe top of said gas pass and conducting steam from th steam and Waterdrum to the second superheater section, the tubes of the secondsuperheater section being connected to the first superheater section forsteam fiow from the second section through the first, a bank ofhorizontal economizer tubes disposed below the tubes of the secondsuperheater section and extending at 90 thereto, and additional meansproviding heat absorbing walls of the gas turning space, said additionalmeans including rows of upright economizer outlet tubes extendingupwardly past the second superheater section and acting as supports forthe bank of economizer tubes.

3. In a steam generator-superheater installation, steam generating tubessome of which are wall tubes defining the boundaries of a furnace, asteam and water drum communicating with the outlet ends of the steamgenerating tubes, means for firing the furnace, means providing a fur-'nace outlet zone of horizontal providi g an upright gas pass ofhorizontal gas flow, a primary superheater gas flow, means beyond saidzone s ction inc udin a plurality iqf ,n ultiple-= loep teturninendatues 11y ithe floyv of gases hea e section ec esupe heate se --ml ltin1loo t be zhQriz'ontal-ga flo n-sup pos d in, a row .elon

#19 5 wh r :t e ea e urnrfmmihmti through said furnace outlet zone 6.0riz nta c tenq h l ti n r lsu than,wetness- DQS. extendin up a. id a lsl i r toflithe n imamsuperhea e 'se t on;

miner= cutletatubesziormins gas coolne walla? gas-turnina nac adsupmttsriontha eener. .:I-n .a steamrsene at zsupe heate ainsta latemrsteamgeneratin tubessome o l-whi he wall @tubes zdefinin it eboundari le ia inmate :1 asteam cand watersdrum communicating with the Joutlet ends ofhe, steam generating ztubes means :fcr firing the-furnace,means l-providine a; furna e outlet zone. of horizontal-gas ffiQWineans-mgovim vring an uprigh eas pass beyond a aid en o horizontal igas--;flow, .-.a v primary supBrheaten-sa- 11101). sincluding a pluralityof ,serially connected and -.spaeed tubes i. extending horizontallyacross the flowrofigasesein saidegas pass; andconnected Vito: verticallyextending tubes ,disposed-iwithinthe ozone. ofhorizontalgasflow, a.secondesuperheatgr sectionreceivingesteam 1from;-the,-primar-y;superheater section and includingi a;plura1ity;025811193 ,connecte'dtubeisections, verticallyglispesedacross ithe-ihorizontal ,agas flow,superheater inlet tubes disposed in arow alongiaiwall effthenup ii htgas pass where the gases turn :from nprizontal :flow :to .adownwardsflow, -,a :bank of shorizontally exitendingeconomizergtubesdisposedbelow-ithe; tubes of the -primary superheater section, theieconomiz'erJtubes extending -at might .angles :to the hotizontal-tubesof theprimary superheater, and economizer outlet :tubes extending; upwardlyiin lwall formation onopposite sides of the npright egas pass and onopposite asides of 5 the bankeof I the horizontal. tubes. of thepri-marylsuperheater section, said economizer outlet tubes formingsupports for the economizer and defining walls for said gas turningspace disposed at to the row of superheater inlet tubes.

5. In a steam generator, a steam and water drum, steam generating Walltubes defining boundaries of a furnace and having their upper endsconnected to the steam and water drum, 2 high temperature superheatersection consisting of serially connected and vertically extendingtubular sections exposed to the heat of the furnace gases in the hightemperature zone of the gas outlet of the furnace, means providing for adownwardly extending gas pass leading from the furnace gas outlet, therebeing a space at the top of the gas pass for turning of the gases, asecond superheater section consisting of horizontally extending seriallyconnected tubes disposed across the gas flow in said downwardlyextending gas pass, the tubes of the second superheater section beingconnected to the tubes of the first for series flow of steam through thetubes of the second and then through the tubes of the first superheatersection, means for conducting steam from the steam and water drum to thetubes of the low temperature superheater section, said last named meansincluding wall tubes along a wall of said gas turning space, aneconomizer including a bank of horizontal tubes disposed below the tubesof the second superheater section and extending at 90 thereto, andeconomizer outlet tubes extending in wall formation upwardly past thesecond superheater sections and said gas turning space.

6. In a vapor generating and superheating unit, a furnace having wallsincluding upright vapor generating tubes, means firing the furnace, wallmeans providing a gas pass disposed laterally of the furnace, the gaspass being constructed and arranged to receive the gas from the furnacefor vertical flow of the gases therethrough, other wall means providingfor substantially horizontal flow of gases from the furnace to the gasinlet of the gas pass, a first superheater section includinghorizontally spaced and series connected: lengths of superheater tubesdisposed vertically across the horizontal flow of gases from the furnaceto the gas pass, a second superheater section including verticallyspaced lengths of superheater tubes disposed horizontally across thevertical fiow of gases in the gas pass, the superheater tube lengthsacross the horizontal gas flow being directly connected to some of thesuperheater tube lengths in the gas pass so that there is series flow ofvapor from one superheater section to the other, the tubular elements ofthe superheater sections and the gas flow wall means being so arrangedthat at least the major portion of the gases of the horizontal gas flowand at least the major portion of the gases of the vertical gas flowflow across the associated superheated tube lengths.

7. In a vapor generating and superheating unit, a furnace having wallsincluding upright vapor generating tubes, means firing the furnace, wallmeans providing a gas pass disposed laterally of the furnace, the gaspass being constructed and arranged to receive the gas from the furnacefor vertical flow of the gases therethrough, other wall means providingfor substantially horizontal flow of gases from the furnace to the gasinlet of the gas pass, a first superheater section includinghorizontally spaced and series connected lengths of superheater tubesdisposed vertically across the horizontal flow of gases from the furnaceto the gas pass, a second superheater section including verticallyspaced lengths of superheater tubes disposed horizontally across thevertical flow of gases in the gas pass, the superheater tube lengthsacross the horizontal gas flow being directly connected to some of thesuperheater tube lengths in the gas pass so that there is series flow ofvapor from one superheater section to the other, the tubular elements ofthe superheater sections being distributed entirely across thehorizontal flow and the vertical gas flow in the gas pass.

8. In a vapor generator, a furnace including vapor generating walltubes, a vapor superheater including banks of unitary tube sections'each having two directly united legs angularly and transversely relatedto each other, means constituting a gas pass having directly joined andtransversely related legs, the angle of the transversely related legs ofeach tube section being oppositely opening relative tothe angle of thetransversely related gas pass legs, parallel and correspondingsuperheater tube legs extending transversely of substantially horizontalgas flow in one gas pass leg and the remaining superheater tube legsextending transversely of upright gas flow in the other gas pass leg,and a superheater header connected to the lowermost part of the unitarysections whereby the superheater is drainable by gravity, adjacentsuperheater tube legs remote from the header having direct connectionsonly at their ends most remote from the header.

RAYMOND J. BOYER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,207,247 Frisch July 9, 19402,287,129 Pyle June 23, 1942 2,293,040 Bailey Aug. 18, 1942 2,330,240Raynor Sept. 28, 1943 2,354,059 Rehm July 18, 1944 FOREIGN PATENTSNumber Country Date 367,276 Great Britain Feb. 18, 1932

